#khung{
    width: 420px;
    margin: auto;   
}
#login{
    margin-top: 200px;
    padding: 10px;
    border: 1px solid darkseagreen;
    border-radius: 2px;
    background: #eee;
}
input [name="userName"],input [name="passWord"]{
    width: 45%;
    padding: 5px 3px 5px 3px;
}
input[name="submit"]{
    background:darkcyan; color: #fff;
    font-weight: bold;
    border: 0px;
    padding: 5px 15px 5px 15px;
}
input[name="submit"]:hover{
    background:lightseagreen;
    color:#000;
}